Move write logic to OAP Server. (#101)

Author: wankai123

src/main/java/org/apache/skywalking/banyandb/v1/client/AbstractBulkWriteProcessor.java

@@ -44,6 +44,7 @@ public abstract class AbstractWrite<P extends com.google.protobuf.GeneratedMessa
 
     protected final Object[] tags;
 
+    @Getter
     protected final MetadataCache.EntityMetadata entityMetadata;
 
     public AbstractWrite(MetadataCache.EntityMetadata entityMetadata, long timestamp) {
@@ -71,7 +72,7 @@ public AbstractWrite<P> tag(String tagName, Serializable<BanyandbModel.TagValue>
         return this;
     }
 
-    P build() {
+    public P build() {
         BanyandbCommon.Metadata metadata = BanyandbCommon.Metadata.newBuilder()
                 .setGroup(entityMetadata.getGroup()).setName(entityMetadata.getName()).setModRevision(entityMetadata.getModRevision()).build();